单如果语句需要开始与代码块

我有点前跑进为此，想知道为什么“开始” &“结束”是需要产生正确的价值观。 if语句是单例，并且不需要“开始”&“结束”，其中if中的多个语句将需要它，并且如果省略，则在尝试创建/更改过程时会产生执行错误。单如果语句需要开始与代码块

任何想法，为什么在MS SQL出现这种情况?????

谢谢，克雷格

- 结果集2返回正确的值。

SQL。

Declare @Qty DECIMAL(10,2), @UOM VARCHAR(5), @CasePack Numeric(7,1), @CaseQty Numeric(11, 4), @im_weigh_item SmallInt, @rank_wi_ven_ctg Char(1), @po_qty_uom Char(1), @po_Qty float 

Select 
    -- these 2 Params are Const in this process 
    @im_weigh_item =0, @rank_wi_ven_ctg = 'C', 
    -- Set Values 
    @UOM = 'C' , @po_Qty_uom = 'M', @po_Qty = 3, @casepack =6, @Qty = 2 

/* 
    Check and Set vars. accordingly 
    This Conditional Block Generates no errors, but the results are incorrect 
    ** NO "Begin" & End" 
*/ 
If(@im_weigh_item=1) 
    If(@rank_wi_ven_ctg='U') 
    Select @UOM = 'U' 
Else 
    If(@po_Qty_uom != 'C') 
    If(@[email protected]) 
    Select @UOM = 'U', @Qty = @Qty * @po_Qty 
-- Debug 
Select @po_Qty_uom as po_Qty_uom, @UOM as UOM, @casepack as casepack, @po_Qty as po_Qty, @Qty as Qty 
-- Debug 

-- reset vars, test 2 
Select @UOM = 'C' , @po_Qty_uom = 'M', @po_Qty = 3, @casepack =6, @Qty =2 

/* 
    *** Works *** Calcs Correctly 
    Check and Set vars. accordingly 
    *** This Block uses the "Begin" & "End" 
*/ 
If(@im_weigh_item=1) 
begin 
    If(@rank_wi_ven_ctg='U') 
    Select @UOM = 'U' 
end 
Else 
begin 
    If(@po_Qty_uom != 'C') 
    If(@[email protected]) 
    Select @UOM = 'U', @Qty = @Qty * @po_Qty 
end 

-- Debug 
Select @po_Qty_uom as po_Qty_uom, @UOM as UOM, @casepack as casepack, @po_Qty as po_Qty, @Qty as Qty 
-- Debug

来源

2010-07-07 Craig

我想如果没有BEGIN和END应该只包含一条指令。我建议将BEGIN .. END添加到每个IF，以帮助保持您的编码一致。

来源

2010-07-07 12:21:21 munissor

添加明确BEGIN S和END s到你破碎的版本产生这一点，这不具有相同的逻辑，你的工作版本：

If(@im_weigh_item=1) 
BEGIN 
    If(@rank_wi_ven_ctg='U') 
    BEGIN 
     Select @UOM = 'U' 
    END 
    Else -- this "else" is associated with the wrong "if" 
    BEGIN 
     If(@po_Qty_uom != 'C') 
     BEGIN 
      If(@[email protected]) 
      BEGIN 
       Select @UOM = 'U', @Qty = @Qty * @po_Qty 
      END 
     END 
    END 
END

来源

2010-07-07 12:23:50 LukeH

ELSE语句总是结合最近的前IF不ELSE，所以你

If(@im_weigh_item=1) 
    If(@rank_wi_ven_ctg='U') 
    Select @UOM = 'U' 
Else 
    If(@po_Qty_uom != 'C') 
    If(@[email protected]) 
    Select @UOM = 'U', @Qty = @Qty * @po_Qty

被解释为：

If(@im_weigh_item=1) begin 
    If(@rank_wi_ven_ctg='U') begin 
    Select @UOM = 'U' 
    end 
    Else begin 
    If(@po_Qty_uom != 'C') begin 
     If(@[email protected]) begin 
     Select @UOM = 'U', @Qty = @Qty * @po_Qty 
     end 
    end 
    end 
end

来源

2010-07-07 12:30:33

单如果语句需要开始与代码块

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